Cutter head



Nov. 12, 1940.

E. P. SACREY CUTTER HEAD Filed Sept. 16, 1938 2 Sheets-Sheet l ManxATTORNEYS.

NOV. 12, 1940. EY 2,221,458

CUTTER HEAD Filed Sept 16, 1938 2 Sheets-Sheet 2 ATTORNEYS.

Patented Nov. 12, 1940 UNITED STATES PATENT OFFICE CUTTER HEAD Elmer P;Sacrey, Syracuse, N i Y. Application selitember 16, 1938, Serial No.230,297 4 Claims. (01. 144-230) This invention relates to rotary cuttersor-cutter heads for power operated tools, and has for its object acutter or cutter head for tools, such as woodworking tools, as powerplanes and jointers, by which the knife or knives can be quicklyadjusted to properly locate their cutting edges in .cutting position andin sharpening position, so

that the knives can be quickly sharpened without demounting them fromthe head by rotating the head in juxtaposition to a grinding Wheel.

The invention consists in the novel features and in the combinations andconstructions hereinafter set forth and claimed.

.In describing this invention, reference is had.

to the accompanying drawings in which like characters designatecorresponding parts in all the views. 1 i

. Figure l is a side elevation of a cutter head embodying thisinvention.

Figure 2 is an end View thereof.

.ure 2,Ia toolfor operating thecam to shift the knives being also shown.I Figures 4, 5 and 6 are sectional. views on lines 4-4, 5-'?-5 and 6-6,respectively, Figure 1.

. t Figure '7 is a rear face view of one of the knives.

Figure 8 is a fragmentary elevation, partly in section, of a poweroperated tool or planelshowing the cutter mounted therein.

Figure 9 is an end view, partly broken away, looking to the right inFigure 8. r H This cutter comprises, generally, a body or headcylindrical in general form, a knifesecured to the head and extendinglengthwise thereof, the knife being arcuate in cross-section andarranged with the cutting edge extending beyond the periphery or arcuateand each is provided with cutting edges ofthe head, and means carried bythe head for shifting the knife aboutthe axis of its'arcto project thecutting edge different distancesv beyond :the periphery of the head, theknife being shiftable into two positions, one being a cutting position,and the other a sharpening position. The knife is arranged with itsconcave side outward. Preferably, a plurality of equally spaced knivesare used and in the illustrated embodiment of the invention, two knivesare used located on diametrically opposite sides of the head. i Idesignates the head, and 2 the knife, The

head iscylindrical in general form and provided with grooves or recesses3 concave or. arcuate in cross-section, located on diametricallyopposite sides of the head. Theknives arealso' concave 4 along oppositeedges thereof. One edge only of each knife is ,used', and thet'knife isreversible Figure 3 is a sectional viewon line 3-3, Fig-' for bringingeither edge 4 into cuttingposition. The arcuate knives 2 are nested inthe grooves 3 and are shiftable about the center 5 of the arc of thebottom of the groove 3 or of the arc of the knife 2.

, -5 In Figures 2, 5 and 6, the knives are in their normal positions orin their positions used for planing. In Figure 4, the knives are shownin their outward shifted positions for grinding or sharpening, V

. l0 The shifting of the knives from the position shown in Figure 2 tothat shown in Figure 4 changes the angle of the edge 4 from the backedoff position with respect to a circle C touching the cutting edge 4 intoa position in which the edge 15 grooves 3, and as here shown, these pins8 extend 25 into grooves 8 formed in the knives. There are two grooves 8in each knife, one groove coacting with the pin 8 when one edge 4 isused for cut-- ting, and the other groove coacting with a pin, when theknife is reversed in the groove 3, and the other edge used for cutting.

The rock shaft 6 is operable from the periphery of the head I and ishere shown as provided with a radially extending arm 9 extending througha radial recessor slot It) in the head and opening through theperipherythereof. This slot is provided with wider end portions II. The arm9 isfor the purpose of receiving a small socket wrench W by means of whichthe cam can be shifted. The head portion of the socket wrench isprovided with a narrower portion which moves through the narrowportionof the slot In between the widened ends, during the shifting ofthe lever from the position shown in Figure 3 to the opposite posi tion,and vice-versa. Obviously, such shifting of i the arm'9 will rotate therock shaft 6 and cause the cam or eccentric pins 8 to shift the knives2. There is a complemental slot I2 in the head diametrically oppositethe slot l0, this having also wider end portions l3, so that thehead isbal- O anced. -The rock shaft 6 has an arm [5 movable in theslot I2,this being bifurcated and its arms sprung outwardly to coact withnotches or grooves l6 formedin the side wall, of the slot [2 and-locatedto receive the bifurcations of the arm I5, when the rock shaft is in oneor the other of its shifted positions. Similar slots or grooves l6 areformed in the walls of the slot Hi1 primarily to counterbalance thediametrically opposite portions of the head.

The knife is held in its position by suitable bolts ll extending throughopenings it near opposite ends of each knife and threading into nuts 19of suitable shape to lie on the concave surface of the knife. Thesenuts, as seen in Figure 1, are formedwith elongated heads extendinglengthwise of the knives 2. The holes l8 are of suflicient diameter topermit the shifting of the knife from its position shown in Figure 2 tothat shown in Figure 4. The heads ll of the bolts are located insuitable depressions or countersinks opening through the periphery ofthe head and are formed with angular recesses to receive a tool fortightening and loosening them. This tool is one end 28 of the wrench W.Also, as seen in Figures 6 and 7, the head is provided with suit-.

able locating pins 2i extending into the bottoms of the grooves i forcoacting with transverse recesses 22 in each knife 2. The head is alsoformed with suitable indicating means, as the words Plane and Grind topointout the position in which the rock shaft is located.

The cutter head is provided with an axially threaded spindlev 23 at oneend for threading into a socket 24 at the end of the armature shaft 25of an electric motor M and with a spindle 28 at its other end journalledin a. bearing 21 supported from the frame 28 of a power tool or plane towhich the motor M is attached.

In operation, the knives 2 are placed in the grooves 4 and located bymeans of pins 2|, the holes 18 of the knives passing over the screws ll.The nuts l9 are threaded loosely on the screws H or the screws ll turnedloosely into the nuts.

When the knife is placed in the groove, one or the other of the slots orgrooves 8 will receive the eccentric pin 8. The rock shaft is thenturned by means of the wrench W until the end of the arm 9 registerswith the indicating word Plane on the periphery of the head I. If, whenthe knife is so placed, the arm 9 is not in such position, the screwsare then tightened and the tool is ready for use; When the knives becomedull, the-screws l9 are loosened; the arm 9 then swung into grindposition, by mean-s of the wrench W; the screws again tightened,whereupon the knives are now in grinding position, shown in Figure 4.The head is then rotated either into position in the tool or isdemounted from the plane and mounted on a rotating center and a rotatinggrinding wheel brought in juxtaposition to the head and knives, andwhile the head and the grinding wheel are rotating, the grinding wheelis fed along the head. The grinding attachment with the wheel forms nopart of this invention, but it is built to hold and feed the grindingwheel in accurate relation to the head while the head is rotating.

When the knife is in plane position, it is in the position shown inFigure 2 and in full lines (Figure '7) with the eccentric pin toward oneend of one of the grooves or slots 8 As seen in Figure 2, the cuttingedge is of greater radius from the axis of the head than the heel 4 ofthe knife. As the cutting edge wears down, its radius approaches that ofthe heel 4 'Then upon turning ofthe rock shaft 6, after loosening thescrews l9, the knife is shifted outward into the position shown inFigure 4, the eccentric pin 8' moving along the slot 8 to the centerthereof,

again loosened and the rock shaft 6 operated back to plane position. Theeccentric pin, during this operation, again moves toward one end of theslot 8 from the position shown in dotted lines (Figure '7) to that shownin full lines. The screws Iii-are then tightened.

, In such tools, as power planes, the motors are detachable and insharpening this tool, the motor with the cutter head thereon isdemounted as a unit, and the unit mounted in a fixed relation to thewheel of the grinding attachment.

When one cutting edge of each knife is worn out, the knife is reversedin its groove.

- What I claim is:

1. A rotary cutter comprising a head, knives mounted on diametricallyopposite sides of the head and extending lengthwise of the axis thereof,each knife being arcuate in cross-section with the cutting edgeextending beyond the periphery of the head, and means for shifting theknives simultaneously about the center of their arcs including a memberrotatably mounted in the head and mounted with its axis extendingdiametrically of the axis'of the head and having eccentric pins at itsends coacting respectively with the knives, the knives having slots inwhich the pins work cam-fashion, and means operable.

from the periphery of the head for rocking the, cam about its axis.

2. A rotary cutter comprising a head having a lengthwise peripheralgroove, arcuate in crosssection, and a knife, arcuate in cross-section,nested in the groove and projecting along one edge out of the groove,and mechanism for shifting the knife in the groove about an axis locatedat the center of the arc of the groove and the knife for shifting thecutting edge of the knife relatively to the peripheral surface of thehead to project different distances out of the groove, said meanscomprising a rocking member mounted in the head centrally thereof andhaving an eccentric pin extending .into the groove, the rocking memberbeing arranged with its axis extending transversely of the axis of thehead and the knife having a groove for receiving the eccentric pin, andmeans operable from the outside of the periphery of the head forrotating in said bore with its axis extending crosswise of the axis ofthe head and having an eccentric pin slidably interlocking with theknife, and a rock arm extending into said slot-for operating the rockingmember, and terminating short of the periphery of the head.

4. A,.cutter comprising a head formed with lengthwise peripheralgrooves, arcuate in crosssection, located on different sides thereof, abore extending transversely of the axis of the head and opening throughthe bottoms of the grooves, .15

knives, arcuate in cross-section, nested in the grooves with the cuttingedge of each extending beyond the periphery of the head outside of itsgroove, the head being also formed with radial slots opening into thebore and through the peripheral wall of the head, a rocking membermounted in said bore and having eccentric means at its ends slidablyinterlocking with the knives to shift the knives synchronously toproject their 10 cutting edges difierent distances out of the groove tochange the angle of the cutting edge, the knives housing lengthwisegrooves in which the eccentric means work, a pin projecting radiallyfrom the rocking member into one of said slots by means of which pin therocking member is rocked about its axis, the rocking member also havingan arm extending into the other slot and coacting with notches in thewalls of the slot to hold the rocking member in its shifted position.

ELMER P. SACREY.

